Condenser.



Ax PRUESSMAN.

CONDENSER.

APPLICATION FILED DEC. 18. l9l6.

Patented Mar. 25, 1919.

ln ven for: A Merl P/uessman UNITED STATES PATENT oriuou.

ALBERT ZERUESSMAN, OF BERWYN, ILLINOIS, ASSIGNOR .TO WESTERN ELECTRIC COMPANY, INCORPORATED,

YORK.

To all whom it may concern .Be it known that I, ALBERT PRUESSMAN, a citizen of the United States, residing at Berwyn, in the county of Cook and State of Illinois, have invented certain new and usefu'l Improvements in Condensers, of which the following is a full, clear, concise, and exact description.

.This invention relates to condensers, and in particular to condensers of the multiple type.

- There is a considerable demand in the telephone field for. condensers which are very closely balanced in capacity with respect to each other, these condensers being required particularly for use on composite, lines used for the simultaneous sending of telephone. and telegraph messages. Also in various other circuits it is required that the condensers used be of the same capacity within very close limits, in order to avoid objectionable cross-talk and to insure the T proper functioning of the circuit as 'designed.

Heretofore, in order to meet the demand for balanced condensers, it has been the general practice to resort to a process of selection, the individual condensers being accurately tested and assigned to different groups.

depending upon the measured capacities of the units, Such a process is not only unsatisfactory and' expensive, but it does not provide for errors resulting from temperature corrections as made under commercial manufacturing conditions; neither does it make allowance for the different rate at which condensers made under slightly different conditions may vary in capacity when sub ected to severe service conditions.

The object of h1s lnvention is primarily a to produce a condenser of the balanced type which will eliminate the trouble now ex perienced, necessitating the selection of condensers and placing themin groups, each group containing condensers held within close capacity limits A further object is .to produce a .multiple-' unit condenser, the units of-which"are not only of the'same capacity when'first made, but the materials and manufacturingprocesses of which are the same for each unit, thereby assuring that capacity changes due to changes in temperature orother causes will be the same for each unit.

nary temperatures.

OF NEW YORK, N. Y., CORPORATION OF NE CONDENSER.

Specification of Letters Patent. t t 25, 9 Application filed December 18, 1916. Serial No. 137.602. i

y I f To accomplish these objects this invention provides a multiple condenser in which a common container is employed for the condenser units required to be closely balanced,

' of these strips of foil being placed on either side of one of the strips of insulated material, and terminals being provided for each strip of conducting foil.

Under certain conditions it is found desirable .to mount two or more of these double units within a single container, and select the individual units to be connected in multiple, so as to give the closest balance This invention will be better understood by reference to the drawing, which is a perspective view. illustrating the strips of foil and insulating material assembled into the form of an elliptical cylinder, T.wo layers of insulating material, each consisting pre erablv of one or more" sheets of thin paper 1 l, are rolled with alternate layers of tin foil into the form of an elliptical cylinder 2, each layer of foil consisting of two separate strips 3, placed a short distance apart and located so that the edges are in aline- 1 ment'with the edges of the opposing strips of foil in the other layer. Terminals 4:, consisting of strips of conducting materlal,

strips of foil during theaw'inding process,

of foil.

Afterthe alternate layers of foil and 1n: sulating paper have been wound, the resulting cylinder is treated in the standard manner and placed within a metal container.

.one terminal being provided for each strip I A preferred way of treating this cylinder isto first dip it in melted paraffin wax-or equivalent material, and then Sub ect it to slight pressure while it is allowed to cool Y and set. It is then dipped into a molten 1nsulating compound wh1ch solidifies at ordr ping process, the unit is protected. by a layer of insulating compound- It is then placed in a metalcontalner, which has already been covered to a slight As a result of thisdipi the bottom of preferably of copper, are connected to the 9 depth by a pouring of the insulating com-, pound, and an additional pouring of compound is made extending over the terminal strips 4:; thereby completely surrounding the condenser unit With insulating compound.

With this construction it Will be noted that the Variationsresulting from difierences in the insulating paper and in the manufacturing processes are eliminated, and

' it is not necessary to consider the inconsistplaced in a,

2. A multiple condenser comprising a cylindrical structure having a plurality ofindependent parallel convolutions of conduct ing material of equal length separated by convolutions of a dielectric common to a plurality of other conducting convolutions of equal length to form a plurality of inde-. a

pendent similar balanced condenser units.

3. The method of forming a multiple condenser Which consists in placing a plurality of electrically distinct conducting sheets of equal Width and length in alinement With a plurality of other electrically distinct conducting sheets of equal length and Width but separated therefrom by a layer of non-conducting material and then inding said sheets into a unitary structure, thereby forming a plurality of independent balanced condenser units having identically the same characteristics.

In Witness whereof, I hereunto subscribe 12th day of Dec. A. D., 1916.

my name this s ALBERT PRUESSMAN. 

